Ferrite memories



March 3, 1970 1'. VAN KHAI 3,498,764

FERRITE MEMORIES FledMarch 28, 1966 FIG.2

United States Patent O 3,498,764 FERRITE MEMORIES Tran van Khai, Paris,France, assignor to CSF-Compagnie Generale de Telegraphe San Fil, acorporation of France Filed Mar. 28, 1966, Ser. No. 537,746 Int. Cl.H01f 7/06; G11b 5/00 U.S. Cl. 29--183 5 Claims ABSTRACT OF THEDISCLOSURE The present invention relates to the manufacture of ferritewafer memories.

It is known to use for the manufacture of such memories a groovedferrite block into which the control wires are fitted and which isassembled together with a ferromagnetic layer of an iron-nickel alloydeposited on a glass substratum. This results in a structure having acertain airgap and therefore a certain fragility and a somewhatdefective protection against external effects.

It is an object of this invention to provide a more robust memory withbetter protection against external factors in which the gap is filledwith an insulator.

According to the invention there is provided a ferrite memory comprisinga ferrite plane block; a first network of parallel conductors on saidblock; a second network of parallel conductors on said first networkintersecting said first network, said parallel conductors of said secondnetwork Ibeing insulated from said parallel conductors of said firstnetwork; and a ferromagnetic layer covering said block and said firstand second networks, said layer being insulated from said parallelconductors of said networks.

For a better understanding of the invention and to show how the same maybe carried into effect reference will be made to the drawingsaccompanying the following description and in which:

FIG. 1 shows a plan View of a ferrite block prior to the removal of thesuperfluous insulating material;

FIG. 2 is a cross-section along the line I-I of the block in FIG. 1;

FIG. 3 is a perspective view of the ferrite block after the removal ofthe surplus insulating material; and

FIG. 4 is a cross-section along the line II-II of the block of FIG. 3after the depositing of the ferro-nickel layer.

The same reference numerals designate the same elements throughout allthe figures.

V 3,498,764 ce Patented Mar. 3, 1970 FIGS. l and 2 show, in plan viewand in cross-section respectively, a ferrite -block 1 according to theinvention prior to the removal of the superfiuous insulating material.On the ferrite block 1 is deposited a network of parallel conductors 2,for example by evaporating under a vacuum, and then an insulating layer4. In the case of evaporation under a vacuum, this layer will preferablybe of silica. Next a second network of conductors 3 is deposited atright angles to the first network and then a second layer of insulatingmaterial 5. The insulating material is then removed where there are noconductors, and a block of the type shown in perspective in FIG. 3 isobtained. On this prepared surface of the ferrite block, a ferromagneticlayer of an iron-nickel alloy 6 is deposited, for example byelectrolysis. The ferromagnetic layer 6 assumes the shape of thissurface, as shown in FIG. 4.

Of course the invention is not limited to the embodiment described andshown which was given only by way of example. In particular, theinsulating and ferromagnetic layers may be applied by any known methodwithout thereby departing from the invention.

What is claimed is:

1. A ferrite memory comprising a ferrite plane block; a first network ofparallel conductors on said block; a first network of insulatingparallel strips covering respectively said conductors and a secondnetwork of parallel conductors on said first network intersecting saidfirst network, said parallel conductors of said second network beinginsulated by said insulating parallel strips from said parallelconductors of said first network; a further network of insulatingparallel strips covering respectively said conductors of said secondnetwork; a ferromagnetic layer covering said block, said insulatingparallel strips and said further insulating network.

2. A ferrite memory as claimed in claim 1, wherein said ferromagneticlayer is of an iron-nickel alloy.

3. A ferrite memory as claimed in claim 1, wherein said first and secondnetworks intersect at right angles.

4. A ferrite memory as claimed in claim 1, wherein said networks areinsulated from each other by means of silica.

5. A ferrite memory as claimed in claim 1, wherein said networks areinsulated from said layer by means of silica.

References Cited UNITED STATES PATENTS 3,281,825 10/1966 Corl 340-174 X3,337,856 8/1967 Bate 340--174 3,362,065 l/ 1968 Lauriente 29--604 L.DEWAYNE RUTLEDGE, Primary Examiner J. E. LEGRU, Assistant Examiner U.S.Cl. X.R.

